For some time hospital patients have been remotely monitored for many conditions. One of the most common is remote ECG monitoring. These monitoring systems operate with transmitters, each at a different frequency, being attached to the patient to transmit the desired signals to a nurse's station via a permanently installed system of antennas within at least the section of the hospital where the monitored patients are located. With each transmitter operating at a different frequency, the signals from each of the antennas are simply added together for transmission to the nurse's station. The console at the nurse's station then isolates one signal from another by frequency, and is able to monitor each patient's ECG or other signal simultaneously.
Since the prior art systems add the signal from each antenna to the signal from each other antenna for transmission, they lack the ability to identify the location of the patient. Thus, the patients that are being monitored are asked to remain within a particular region of the hospital so that they can receive immediate assistance if a distress signal is received at the nurse's station.
Human nature being what it is, coupled with the fact that many of these patients are confined to the hospital for long periods of time, patients often roam outside the area where they are told to stay. They proceed through the halls of the hospital, many of them pulling their wheeled IV racks along with them. If an emergency situation arises when the patient is outside the monitoring area, the monitoring nurse's station may receive a distress signal from the transmitter attached to the patient and not be able to locate the patient.
In at least one recent situation there was a patient who was transferred from one hospital to another with the first hospital's transmitter still attached to him. When a distress signal was received from that patient in the second hospital they were not able to immediately locate the patient. It was only after many hours that they were able to find the patient by sequentially and systematically turning off sections of the hospital's telemetry antenna system and listening for a signal from the patient's transmitter.
It would be desirable to have a patient locating system that could rapidly identify the approximate location of each monitored patient. A system that is also compatible with the remote monitoring of ECG, or another function, of a number of patients would be even more desirable. Yet more desirable would be a system that could be implemented by retrofitting existing hospital telemetry monitoring systems that can be used to locate a monitored patient. The various embodiments of the present invention are believed to offer systems with each of these advantages.